Tigertronics Review:

SkySpy v1.1a By W.F. Schroeder DL5YEC


The author of the famous HamComm multimode program has done it again! This time Mr. Schroeder has written SkySpy, a "real" Windows 95/98 program, designed specifically for the reception of Aircraft Communications And Reporting System (ACARS) transmissions.

Using your BayPac MultiMode, VHF scanner and SkySpy, you can monitor the digital communications between aircraft and air traffic control towers. These digital transmissions contain lots of interesting information, including the aircraft's position, flight number, registration number, airline name, pilot comments and more. Even if you are not close to an airport, chances are that you will still be able to pick up plenty of ACARS activity from distant flying aircraft.

Installation and Configuration

Installing SkySpy couldn't be easier. The program comes with a professional "Installation Wizard" that guides you through the entire process in a matter of minutes. In fact, about the only thing that you will need to enter is the destination directory for SkySpy files!

Configuring SkySpy is also very easy. All you have to do is select the serial port that the BayPac is attached to and then adjust the volume setting on your radio. You can select which serial port you are using from the "Options" menu at the top of the screen, or by clicking the "C1" (COM1) or "C2" (COM2) button on the menu bar. The menu bar also contains a "Receive Signal Indicator" that is used to adjust the radio's volume to the correct level. To set the volume, you simply have to open the radio's squelch control and then slowly advance the volume control until the signal indicator glows green. That's all there is to it! Note that the squelch on your radio must remain open at all times, for the program to function properly.

Using SkySpy - ACARS Reception!

If you don't know what frequencies to monitor for ACARS activity in your area, you don't have to worry! SkySpy's on-line help file contains frequency listings for the United States, Canada, Europe and Japan. During our testing, we simply tuned to the U.S. primary ACARS frequency of 131.550 MHz.

Even though our facility is located more than 40 miles from the nearest airport, we were still able to receive plenty of ACARS activity. Surprisingly, we were able to decode nearly every transmission that we could hear! Only one time did we receive a message that contained an error. Some of the messages that we received can be seen in the picture of SkySpy's "List" window shown below.

The List window allows you to browse through all the messages that are stored in SkySpy's database. When you find a message that looks interesting, you can double-click on it to bring up a "Message" window for that particular transmission. The Message window displays all of the ACARS data in an easy to read format. The picture shown below is the Message window for one of the ACARS transmissions that we received.

Other Features

SkySpy also features a "Monitor" window (not shown) that displays the activity of the SkySpy decoder. In this window you can view the raw message data as well as the message "status". The raw message data shows every character, exactly as it was received. Note that non-printable characters will be enclosed in "<>". This screen can also be used to analyze special messages. The message "status" can tell you several things about the transmission. For example, if the message was received with errors, then it will have a status of "parity?" to indicate that a parity error has occurred. If the message is the first message to be received from a particular aircraft, then it will have a status of "new" displayed. Duplicate messages are given a status of "dup" to indicate that the message is an exact copy of a previous message.

Another nice feature of SkySpy is the ability to save all received data to disk. Data from both the List and Monitor (*.LOG and *.MON) windows can be saved, so that you can view them at a later time. All of the files are saved in ASCII format, so that they can be viewed with any ASCII text editor. They can also be viewed from within the SkySpy program.

Suggested Improvements

The only suggestion for an improvement, that we would recommend, is the addition of support for serial ports 3&4. In this day and age, where nearly everyone already has a mouse and telephone modem installed, it is almost inevitable that new accessories will have to be installed on one of these ports.


If you are interested in monitoring ACARS activity, then SkySpy is the program for you! It is inexpensive, easy to use, and it delivers superb performance, without any compromise. For more information, or to order a copy of SkySpy, you will need to visit the Pervisell Ltd. web site (www.pervisell.com).

Program Requirements:

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